Microsoft and Digital Realty offer 2 unique approaches to data center water use

Microsoft and Digital Realty, one of the world’s biggest data center companies, are separately embracing new and unique approaches to reduce the water required to keep computers and network gear from overheating as demand for artificial intelligence and cloud computing services spikes.

For Microsoft, the answer is in the form of a new data center design it adopted in August that uses recycled water and chip-level cooling technology to deliver cooling directly to computing racks handling AI workloads. When the system is filled during construction, it is filled with water that circulates between IT equipment and chillers and then sealed. 

While water is used for other purposes, such as in restrooms or on-site kitchens, the change — which will apply to all new sites — will avoid water withdrawals of 125 million liters per year, the company said in a Dec. 9 blog post. The approach will result in a “nominal” increase in energy consumption compared with Microsoft’s existing data center designs, said Steve Solomon, vice president of data center infrastructure engineering at Microsoft.

“Additional innovations to provide more targeted cooling are in development and are expected to continue to reduce power consumption,” Solomon said.

New projects for Phoenix and Mt. Pleasant, Wisconsin, that come online in 2027 will use the new design.

Source: Microsoft

Water withdrawals a growing concern

The strain data centers put on electricity grids may command more headlines, but concern over their potential to stress water supplies is also growing. As of 2021, 20 percent of data centers were located in water-stressed regions, and research suggests that some can guzzle 5 million gallons daily — an amount equivalent to the drinking water for a town of 50,000 people.

Data center operators use different cooling designs depending on the geography in which they are located. Some in Northern climates are air-cooled but most data centers evaporate water to release heat. 

Microsoft’s new approach is expected to reduce its water usage effectiveness (WUE) — a measure of how much water is used per kilowatt-hour — to nearly zero compared with an average of 0.30 liters per kWh currently. The industry average for WUE is 0.5 gallons per kWh. Amazon Web Services operates with a WUE of 0.05 G/kWh.

AI-driven water conservation

Digital Realty’s water conservation strategy relies on suggestions made by an artificial intelligence service it deployed in collaboration with Nalco Water, a process management business owned, global water services company Ecolab. 

The technology, being used at 35 U.S. data centers that are water-cooled, is expected to help Digital Realty avoid the withdrawal of 126 million gallons of potable water annually — a 15 percent reduction in water use. It works by detecting anomalies that could be signs of system problems such as stuck valves, pump pressure issues or leaks, said Aaron Binkley, vice of sustainability at Digital Realty.

“It helps find hidden opportunities by identifying patterns and data that could guide decisions,” he said. “It’s really a complement to human expertise.” 

The data used by the system comes from existing building management systems, and the payback period is generally less than two years in most locations, Binkley said. Digital Realty is likely to use the technology in other water-cooled data centers; it operates more than 300 worldwide, but the majority don’t use water-cooling.

Ecolab plans to offer this capability to other data center operators as part of its expanding digital services portfolio, said Emilio Tenuta, senior vice president and chief sustainability officer at Ecolab. “As the AI boom accelerates and demand for data centers grows, so do the requirements for water and energy, making innovation in this space crucial for sustainable growth,” he said.

Most data center operators don’t disclose their water consumption, but Amazon Web Services, Google and Microsoft are all talking up the need for more action. Aside from new designs, they’re all investing in water replenishment projects.